Tyrosine
L-Tyrosine / N-Acetyl L-Tyrosine (NALT)
Amino acid precursor to dopamine and norepinephrine, supporting focus and mental performance under stress.
L-Tyrosine is an amino acid that serves as a precursor to dopamine, norepinephrine, and epinephrine. It's most effective for maintaining cognitive performance during stress, sleep deprivation, or demanding tasks. Benefits are most pronounced when catecholamine levels are depleted by stress or fatigue.
Mechanisms of Action
Catecholamine Precursor
Provides building blocks for dopamine and norepinephrine
Stress Buffer
Replenishes neurotransmitters depleted by stress
Recommended Dose
500-2000mg
Optimal Timing
- 30-60 minutes before stressful activity
- On empty stomach for best absorption
Can be taken without food
Best Form
L-Tyrosine powder or capsules
Alternatives: N-Acetyl L-Tyrosine (NALT) — more soluble but may be less effective
L-Tyrosine is better studied. NALT has better solubility but may not convert to tyrosine as efficiently.
Duration
Minimum: 1 days
Optimal: days
Cycling: Best used as needed rather than daily. Chronic high-dose use may downregulate receptors. Use for demanding periods, then take breaks.
Note: Take on empty stomach as it competes with other amino acids for absorption. NALT may be taken with food. Most effective when used acutely before demanding tasks.
Personalized Dosage Calculator
Get a dosage recommendation tailored to your body weight, age, goals, and health profile.
Set up your health profile for personalized recommendations
Maintained Focus Under Stress
Better cognitive performance during demanding tasks
Improved Working Memory
Better short-term memory during stress
Reduced Stress Effects
Less cognitive decline from acute stressors
Insufficient data; likely safe at dietary levels
Consult doctor as tyrosine affects thyroid function
Who Should NOT Take This
- Hyperthyroidism (provides thyroid hormone precursor)
- Melanoma (may promote melanin production)
- Those taking MAOIs
Drug Interactions
May cause dangerous increase in catecholamines
Tyrosine is a precursor to thyroid hormones; may affect levels
May compete for absorption and affect efficacy
Possible Side Effects
Tip: Reduce dose
Tip: Take with small amount of food
Tip: Lower dose; don't combine with stimulants
Warnings
- Most effective during stress — benefits less clear at baseline
- Avoid combining with MAOIs or high-dose stimulants
Caffeine
complementaryBoth support alertness through different mechanisms
Enhanced mental performance; start with lower doses of each
B-Complex
enhancesB vitamins are cofactors in catecholamine synthesis
Supports the conversion of tyrosine to neurotransmitters
Mucuna Pruriens
cautionBoth affect dopamine — may be excessive together
Use one or the other, not both
Top studies from 40+ peer-reviewed papers
Ma Z et al. • BMJ (Clinical research ed.) (2025)
“In patients with EGFR-mutated NSCLC, first and third generation EGFR tyrosine kinase inhibitors, as well as combination therapies with antiangiogenesis, were associated with increased risks of cardiovascular adverse events.”
Key Findings:
- Compared with placebo, both first generation (odds ratio 1.51, 95% confidence interval 1.01 to 2.26; high certainty; pooled incidence 3.2%) and third generation EGFR tyrosine kinase inhibitors (2.18, 1.46 to 3.27; high certainty; 9.5%) were associated with increased risks of cardiac adverse events.
- Among third generation inhibitors, osimertinib (2.53, 1.53 to 4.19; high certainty; 8.9%) and lazertinib (2.84, 1.17 to 6.91; moderate certainty; 2.7%) were associated with cardiac adverse events.
- Also, the risk of arrhythmias was significantly higher with third generation inhibitors (3.26, 1.83 to 5.81; high certainty; 7.3%), such as osimertinib alone (3.35, 1.75 to 6.40; high certainty; 6.2%) and in combination with antiangiogenesis.
Zhao Y et al. • The Lancet. Oncology (2024)
“For individuals with advanced EGFR-mutated NSCLC who progressed on EGFR-TKIs, ICI-antiangio-chemo was identified as the optimal treatment option.”
Key Findings:
- For individuals with advanced EGFR-mutated NSCLC who progressed on EGFR-TKIs, ICI-antiangio-chemo was identified as the optimal treatment option.
- The toxicity of this treatment was acceptable but needs careful attention.
- ICI-chemo showed appreciably greater efficacy than the standard-of-care chemotherapy.
- These findings clarified the roles of ICI-based treatment strategies in this difficult-to-treat refractory population, potentially complementing recent guidelines.
Buchrits S et al. • Annals of hematology (2025)
“This meta-analysis examined the effects of Tyrosine.”
Key Findings:
- Pooled risk ratios (RR) with 95% confidence intervals (CIs) were estimated using fixed or random effects models based on heterogeneity.
- Similarly, BTKi monotherapy was not associated with an increased risk of grade 3-4 infections [RR 1.05 (95% CI: 0.76-1.44, I2 = 61%), 5 trials].
- The risk of sepsis was not significantly increased with BTKi regimens [BTKi + anti-CD20: RR 0.48 (95% CI: 0.12-1.84, I2 = 69%), 4 trials; BTKi monotherapy: RR 0.50 (95% CI: 0.25-1.01, I2 = 0%), 5 trials].
- However, pneumonia risk was increased in the BTKi + anti-CD20 vs other regimens, [RR 2.18; 95% CI 1.29-3.70; I2 = 3%, 4 trials].
Zong S et al. • Frontiers in immunology (2025)
“Seven therapies showed better efficacy than TACE alone for particular patients with intermediate-stage HCC.”
Key Findings:
- Seven therapies showed better efficacy than TACE alone for particular patients with intermediate-stage HCC.
- Published in Frontiers in immunology (2025)
- Further research warranted to confirm findings
Zhang W et al. • BMC pulmonary medicine (2024)
“Our study concluded that combination regimens based on third-generation TKIs (osimertinib plus ramucirumab, osimertinib plus chemotherapy, osimertinib plus bevacizumab, amivantamab plus lazertinib and aumolertinib plus apatinib) could be the new and clinically preferable first-line, standard of care for EGFR-mutated advanced non-small cell lung cancer.”
Key Findings:
- In terms of safety profile, combination therapies based on third-generation TKIs did not significantly increase the incidence of grade 3 or higher adverse events compared with other regimens.
- Published in BMC pulmonary medicine (2024)
- Further research warranted to confirm findings
Study Type Distribution
Goals This Supplement Supports
Related Goals
This information is for educational purposes only and is not intended as medical advice. Always consult a qualified healthcare provider before starting any supplement.